foundationdb/flow/AsioReactor.h

100 lines
2.7 KiB
C++

/*
* AsioReactor.h
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef FLOW_ASIOREACTOR_H
#define FLOW_ASIOREACTOR_H
#pragma once
#include <boost/asio.hpp>
#include <boost/bind.hpp>
#include "flow/flow.h"
namespace N2 { // No indent, it's the whole file
class Net2;
class Peer;
class Connection;
class ASIOReactor {
public:
explicit ASIOReactor(Net2*);
void sleep(double timeout);
void react();
void wake();
boost::asio::io_service ios;
boost::asio::io_service::work do_not_stop; // Reactor needs to keep running when there is nothing to do until stopped explicitly
private:
Net2* network;
boost::asio::deadline_timer firstTimer;
static void nullWaitHandler( const boost::system::error_code& ) {}
static void nullCompletionHandler() {}
#ifdef __linux__
class EventFD : public IEventFD {
int fd;
boost::asio::posix::stream_descriptor sd;
int64_t fdVal;
static void handle_read( Promise<int64_t> p, int64_t* pVal, const boost::system::error_code& ec, std::size_t bytes_transferred ) {
if (ec) return; // Presumably, the EventFD was destroyed?
ASSERT( bytes_transferred == sizeof(*pVal) );
p.send(*pVal);
}
public:
EventFD(ASIOReactor* reactor) : sd(reactor->ios, open()) {}
~EventFD() override {
sd.close(); // Also closes the fd, I assume...
}
int getFD() override { return fd; }
Future<int64_t> read() override {
Promise<int64_t> p;
sd.async_read_some( boost::asio::mutable_buffers_1( &fdVal, sizeof(fdVal) ),
boost::bind( &EventFD::handle_read, p, &fdVal, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred ) );
return p.getFuture();
}
int open() {
fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
if (fd<0) {
TraceEvent(SevError, "EventfdError").GetLastError();
throw platform_error();
}
return fd;
}
};
public:
static IEventFD* getEventFD() { return static_cast<IEventFD*>((void*) g_network->global(INetwork::enEventFD)); }
static EventFD* newEventFD(ASIOReactor& reactor) { return new EventFD(&reactor); }
#endif
};
} // namespace net2
#endif